Natural Curiosities

Q. We are invaded by boxelder bugs every fall. How do we get rid of the problem?

Grant White
Forest Lake

A.These black-and-red insects, which reproduce in summer on female box elder trees, are attracted to the warm, sunny sides of buildings in their search for winter quarters. The good news is they don't sting or bite, and won't harm your furnishings. Caulk holes around your foundation, windows, and other entries to keep out bugs. You can also apply a residual insecticide where boxelder bugs gather on the outside of your house. If they get inside, suck them up with a vacuum cleaner.

Q. A pair of loons has lived on our small lake for 24 years. I last saw them in early June. I also noticed for the first time our lake was inhabited by one hen and eight or nine drake mallards. Could the mallards have chased the loons away? I miss my "Fred" and "Ethel."

Lisa Pelarske
Avon

A. The mallards were more likely opportunists than invaders. According to DNR nongame wildlife specialist Pam Perry, loons can be very territorial and will chase ducks and other birds off a lake so they can have it all to themselves. What likely happened is the loons had tough luck with their nest and hung it up for the year, or one died and the other abandoned the lake. Then, in the absence of loons, the ducks moved in. Perry says loons can live more than 20 years and reproduce throughout their lives. She suggests you watch next spring to see if the pair comes back for another try.

Q. We have been finding painted turtles with a round ball on their shell (same color as the shell, but soft) that seems like a growth. What are these? Also, what kind of frogs are dark green with a yellow throat and make a sound like a bark at night? We rarely see leopard frogs anymore, but see more and more of these green frogs.

Marie Keefe
Lindstrom

A. DNR turtle expert Carol Hall says she's never seen anything like what you describe on a turtle shell, and neither have her turtle expert friends. The growths could be related to an injury or infection, but since you saw them on more than one turtle, they might be due to algae, fungi, or maybe even leeches.

The green frogs you describe are just that-green frogs. Native to Minnesota, they live in deep wetlands or lakes. Green frogs call during June and July. Some people say they sound like someone strumming a loose banjo string.

Q. The blackbirds at our feeder attack the sparrows. We have found several sparrows on the lawn with their heads gone. Is this normal? My son likes to feed the birds and feels bad they can't eat together. Do you have any suggestions?

Alice Baumann
Alexandria

A. The attackers are probably grackles and the victims, house sparrows, says DNR nongame wildlife expert Carrol Henderson. Because nonnative sparrows drive away or kill native songbirds such as bluebirds and chickadees, the grackles are probably doing Minnesota's native birds a favor. To reduce bloodshed in your yard and encourage native species, put out larger seeds such as black-oil sunflower, safflower, or peanuts-or use special feeds like suet or niger thistle. House sparrows don't like those, but native songbirds such as cardinals, goldfinches, and chickadees do.

Q. We have been observing an unusual Canada goose family. A white-headed goose has returned for at least three years and seems to be a member of the family. It seems odd to us that the nesting pair would permit this while dealing with their own young ones. Is this common?

Aaron and Mary Longtine
Lake Park

A. The odd bird is probably a cross between a Canada goose and a blue goose, says retired University of Minnesota professor and goose expert Jim Cooper. Although not exactly common, such crosses have been reported for years. You are right that nesting Canada geese usually hang out in pairs, but occasionally they form family groups of two females and one male. That may be what's happening here. The hybrid would be sterile, so any young would be the offspring of the other two birds.